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Related papers: Invariant information and quantum state estimation

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The Quantum Fisher Information (QFI) is a geometric measure of state deformation calculated along the trajectory parameterizing an ensemble of quantum states. It serves as a key concept in quantum metrology, where it is linked to the…

Quantum Physics · Physics 2025-12-05 Gabriela Wójtowicz , Susana F. Huelga , Marek M. Rams , Martin B. Plenio

The minimum error of unbiased parameter estimation is quantified by the quantum Fisher information in accordance to the Cram\'{e}r-Rao bound. We indicate that only superposed NOON states by simultaneous measurements can achieve the maximum…

Quantum Physics · Physics 2015-05-28 Y. R. Zhang , G. R. Jin , J. P. Cao , W. M. Liu , H. Fan

In recent proposals for achieving optical super-resolution, variants of the Quantum Fisher Information (QFI) quantify the attainable precision. We find that claims about a strong enhancement of the resolution resulting from coherence…

Quantum Physics · Physics 2019-11-14 Zdeněk Hradil , Jaroslav Řeháček , Luis Sánchez-Soto , Berthold-Georg Englert

A novel measure, quantumness of correlations is introduced here for bipartite states, by incorporating the required measurement scheme crucial in defining any such quantity. Quantumness coincides with the previously proposed measures in…

Quantum Physics · Physics 2008-04-20 A. R. Usha Devi , A. K. Rajagopal

We have introduced a measure of Gaussian quantum correlations based on quantum Fisher information. For bipartite Gaussian states the minimum quantum Fisher information due to local unitary evolution on one of the parties reliably quantifies…

Quantum Physics · Physics 2014-06-20 Manabendra N. Bera

In estimating an unknown parameter of a quantum state the quantum Fisher information (QFI) is a pivotal quantity, which depends on the state and its derivate with respect to the unknown parameter. We prove the continuity property for the…

Quantum Physics · Physics 2019-09-16 A. T. Rezakhani , M. Hassani , S. Alipour

We demonstrate that the concept of information offers a more complete description of complementarity than the traditional approach based on observables. We present the first experimental test of information complementarity for two-qubit…

The variance of an observable in a quantum state is usually used to describe Heisenberg uncertainty relation. For mixed states, the variance includes quantum uncertainty and classical uncertainty. By means of the skew information and the…

Quantum Physics · Physics 2012-05-07 D. Li , X. Li , F. Wang , X. Li , H. Huang , L. C. Kwek

We derive a tight bound between the quality of estimating a quantum state by measurement and the success probability of undoing the measurement in arbitrary dimensional systems, which completely describes the tradeoff relation between the…

Quantum Physics · Physics 2012-10-12 Yong Wook Cheong , Seung-Woo Lee

We consider two variants of a quantum-statistical generalization of the Cramer-Rao inequality that establishes an invariant lower bound on the mean square error of a generalized quantum measurement. The proposed complex variant of this…

Quantum Physics · Physics 2007-05-23 V. P. Belavkin

Studies about Quantum Information Theory continue actively in many research institutions. Very recently, pratical setups of large scale quantum computers are widely studied e.g. quantum repeaters, memories and processors. Entanglement…

Quantum Physics · Physics 2017-05-16 Volkan Erol

Quantum Fisher information (QFI) sets the ultimate precision of optical phase measurements and reveals multiphoton entanglement, but it is not accessible with conventional photodetection. We theoretically predict that a photodetector…

Mesoscale and Nanoscale Physics · Physics 2026-04-01 Evgenii Barts , Takahiro Morimoto , Naoto Nagaosa

In this work, we present a lower bound on the quantum Fisher information (QFI) which is efficiently computable on near-term quantum devices. This bound itself is of interest, as we show that it satisfies the canonical criteria of a QFI…

Quantum Physics · Physics 2021-12-03 Akira Sone , M. Cerezo , Jacob L. Beckey , Patrick J. Coles

We present a real-time path-integral formulation of the quantum Fisher information for dynamical parameter estimation. For pure states undergoing unitary evolution, we show that the quantum Fisher information can be expressed as a connected…

Quantum Fisher information, as an intrinsic quantity for quantum states, is a central concept in quantum detection and estimation. When quantum measurements are performed on quantum states, classical probability distributions arise, which…

Quantum Physics · Physics 2012-09-04 Xiao-Ming Lu , Shunlong Luo , C. H. Oh

The question of how irreversibility can emerge as a generic phenomena when the underlying mechanical theory is reversible has been a long-standing fundamental problem for both classical and quantum mechanics. We describe a mechanism for the…

Quantum Physics · Physics 2013-09-20 Cozmin Ududec , Nathan Wiebe , Joseph Emerson

We give an analytical result for the quantum Fisher information of entangled coherent States in a lossy Mach-Zehnder Interferometer recently proposed by J. Joo et al. [Phys. Rev. Lett. 107, 083601(2011)]. For small loss of photons, we find…

Quantum Physics · Physics 2016-11-26 Xiaoxing Jing , Jing Liu , Wei Zhong , Xiaoguang Wang

In quantum resource theory (QRT), asymmetry recognized as a valid resource for the advantage of various quantum information processing. In this paper, we establish the resource theory of asymmetry using quantum Fisher information (QFI). By…

Quantum Physics · Physics 2021-10-07 R. Muthuganesan , V. K. Chandrasekar

Local information objectivity, that local, independent observers can infer the same information about a model upon exchange of independently acquired experimental data, is fundamental to science. It is mathematically encoded via Cencov's…

General Relativity and Quantum Cosmology · Physics 2026-05-19 Per Berglund , Andrew Geraci , Tristan Hubsch , David Mattingly , Djordje Minic

Quantum estimation theory provides optimal observations for various estimation problems for unknown parameters in the state of the system under investigation. However, the theory has been developed under the assumption that every observable…

Quantum Physics · Physics 2009-11-10 M. Hotta , M. Ozawa